Spark plug fouling and pre-ignition caused by hot spark plugs is a significant issue in areas with poor fuel quality control. Fuel additives such as MMT or ferrocene may build up electrically conductive and thermally insulating deposits on the spark plug ceramic. Such build up may cause misfires or pre-ignition (PI). Due to the potential severity of misfires or PI at high speed and load in boosted engines, vehicle manufacturers may recommend very short spark plug change intervals. However, as the issue of misfires and PI due to fuel additive build up is often a geographically and seasonally limited issue, such frequent spark plug changes may be unnecessary for some vehicles.
The inventors have recognized the above issues, and offer a system to at least partly address said issues. In particular, the present disclosure provides low cost and easy-to-implement methods and systems for continuously detecting the fouling level present at the spark plug, detecting the occurrence of PI and warning the customer to change plugs only when conditions warrant. In one embodiment, a method includes providing a dwell command on a control wire of an ignition system and generating an indication of a recommendation to change a spark plug of the ignition system based upon a current on the control wire.
The present disclosure may offer several advantages. For example, by providing spark plug change recommendations based on evidence of malfunction or degradation, rather than a predetermined period of time or amount of vehicle usage, such recommendations may ensure that spark plug change recommendations are provided in a timely manner. The recommendations supported by measured indications of spark plug fouling may ensure that spark plug change recommendations are not provided too soon, resulting in increased cost for the driver, or too late, resulting in damage to the vehicle.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.